Complex search Filters?

I've got 2 entities, Job and Task. The datamodel looks like this: The task Status has the following values: Open In_Progress Closed In a datagrid, how do I display Jobs with ONLY Closed Tasks? In other words, Jobs with NO Open Tasks related to it. It seems the search widget on a datagrid allows only for single value filters. An XPath expression on the grid doesn't help either. This seems like a trivial thing in practice but I'm unable to get my head around an elegant solution. Using a "Search_Entity" that uses a microflow that filters out Jobs that have Open Tasks is a fail, because we are talking about a lot of Jobs which causes Mendix to fall over in terms of memory.
1 answers

This constraint will do the trick (you can omit the //Job of course):

//Job[not(Task_Lead/Task/Status != Closed)]